Ni-based catalysts have advantages of low cost, rich resource and high catalytic activity. However, Ni-based catalyst has a poor resistance to carbon deposition, and thus can be easily deactivated due to serious carbon deposition. How to improve the resistance of Ni-based catalyst to carbon deposition is a focus of both academia and industry. Cold plasma has been widely used in fabricating coke-resistant Ni-based catalysts, due to its low operation temperature and abundant high-energy species. In the present paper, recent progresses in fabricating coke-resistant Ni-based catalysts by cold plasma are reviewed. The influences of the low operation temperature and high-energy species of cold plasma on the properties of supports, Ni-support interactions and Ni nanoparticles are discussed. The origins for the enhanced carbon deposition resistance of the Ni-based catalysts prepared by cold plasma are analyzed. Finally, we propose that increasing the yield of Ni-based catalysts, decreasing the power consumption and combining cold plasma with other techniques like artificial intelligence are the main research directions in the field of preparing coke-resistant Ni-based catalysts by cold plasma.

Recently, carbon dioxide (CO₂) capture utilization and storage (CCUS) has been generally identified as a potential strategy in the global energy transition, enabling the provision of energy and the production of essential materials, while limiting climate change. Due to their large capacity and excellent selectivity for the adsorption of CO₂, outstanding structural properties, as well as their chemical tunability, porous organic polymers (POPs) have been widely employed as efficient catalysts in numerous CO₂-involved reactions. In particular, the insertion of CO₂ into epoxides for affording cyclic carbonates has been proposed as a promising strategy due to its 100% atom economy and the great industrial potential of products. Based on the reaction mechanism together with the synthetic methods, structural properties and component characteristics of catalysts, the progress in POPs for the CO₂/epoxides cycloaddition reaction was reviewed, including metal complexes-, hydrogen-bond donor-, ionic liquids (ILs)-, metal complexes/ILs- and hydrogen-bond donor/ILs-based POPs. The research status and development trend of POPs in the transformation of CO₂ into value-added cyclic carbonate were described, which provided constructive guidance for the development and application of POPs and the industrial exploration of comprehensive utilization of CO₂.

In order to solve the disadvantages of traditional synthesis process for solketal production with low conversion per pass, high investment in production equipment, long post-treatment process and environmental pollution, in this paper, an energy efficient process, reactive distillation (RD) was proposed. Based on the basic data of kinetics and thermodynamics, the strict mathematical model of RD was established, and the theoretical research of RD process was investigated. The influence of the water in RD process was revealed by the analysis of the concentration distribution in the RD column. The impact of the mass of recycled acetone was explored, take reboiler duty of RDC and recovery column as objective function, the parameters of total process were explored and optimized. The results showed that the total energy consumption could be saved by 3.6% compared with the optimization of single column. Compared with the traditional industrial process, the optimized RD process could save energy consumption by 15.1%. The research results can provide basis and reference for the design of solketal industrial production.

In toothpaste process, thickeners such as carboxymethyl cellulose and carbomer tend to form agglomerates in high shear mixers (HSMs),which will cause quality problems as well as disturb normal production. To investigate the influence of different operational conditions of HSMs on agglomerates, the image analysis method based on software Photoshop and Image J was applied to measure the area and total count of agglomerates in a HSM. The influence of rotational speeds, circulating number and total energy input was analyzed. The results showed that the at 1700—2600r/min, the areas of about half number of agglomerates are in the range of 0.5—1.5mm². At 1700—2000r/min, as the circulating number increases, the normalized total count fluctuates significantly. At 2150—2600r/min, as the circulating number increases, the normalized total count decreases without fluctuation. The total energy input is key factor that controls the total count of agglomerates and when total energy input reaches 1000kJ, the total count of agglomerates decreases to the minimum value.

The mixing process, power and torque of straight blade impeller powder mixer were studied by combining numerical simulation with power test. The mixing process of spherical particles in the powder mixer was simulated by discrete element method (DEM). The effects of stirring speed, impeller diameter and blade number on the mixing power and torque were studied, and the power calculation formula was obtained by fitting. A powder mixing test-bed was built to test the power of powder mixing and compare with the simulation results. The results showed that the power consumption in the straight blade impeller powder mixer is closely related to the impeller speed, impeller diameter, blade number and other characteristic parameters. At the same time, torque value and power value were positively correlated with impeller speed, impeller diameter and blade number. The results showed that the torque speed relationship and power speed relationship were similar to the simulation, and the simulation values were in good agreement with the test ones, which verifies the accuracy of the derived formula.

When applying the nodes-based non-structural model (NNM) in optimizing heat exchanger networks, the reasonable adjusting the nodes' parameters (number of stream splitting and the number of groups of stream splitting) can assist the algorithm in obtaining better results within higher efficiency. However, in the setting of NNM model, all hot streams share a set of nodes' parameters and all cold streams share a set of nodes' parameters, thus it cannot customizedly satisfy the requirement of splitting of each stream. To promote the ratio of nodes' utilization in the network, an adjustment strategy was proposed in this paper. This strategy can adjust the number of stream splitting and the number of their splitting groups according to the heat capacities flowrate of streams, which decreases the obstacles resulting from the invalid splitting structures, and obtain the potential superior structures in early optimization period, then improve the optimization quality. 10SP and 15SP were used for proving the validity of strategy in this paper, the results were 340USD/a and 2285USD/a lower than the best ones in literature, respectively. Besides, they are also lower than the ones obtained by the single NNM. The data analysis indicated that this strategy is an effective assistance for improving the performance of the algorithm and contributes to yielding better optimization results.

The poor visibility inside fixed bed reactor during the catalyst dense loading process makes it unable to know the accumulation state of the reactor bed in real time, which affects the filling control and bed quality. A bed surface monitoring system for the catalyst dense loading process was constructed, and the system design included the mechanical structure, electrical control, and software system. The pulse microwave radar was used to obtain the distances of a number of characteristic points, then the spatial distribution was calculated, and the surface image was constructed according to the spatial distribution using cubic spline interpolation under natural conditions. The monitoring effect of the system was tested for materials at various levels, and the influences of ambient light and catalyst particle size on system reliability were discussed. The results showed that the system had the advantages of simple operation and maintenance, high imaging resolution and measurement accuracy, and the monitoring effect at center position was better than that at the edge. The generated three-dimensional blanket image and radial material surface distribution map greatly improved the readability of the bed surface information in dense loading process. The monitoring system is of high robustness and can adapt to the monitoring requirements under multiple working conditions.

Dimethyl carbonate (DMC), methyl formate and methylal etc. are co-products which are not well separated and discharged as waste materials in many coal-to-ethylene glycol plant. As DMC is a valuable and useful raw material in many fields, proper process is needed for DMC rectifying because DMC and methanol forms stable azeotrope and they cannot be completely separated by conventional distillation methods. Pressure swing distillation is chosen after comparing methods of DMC-methanol separation. Three improved process schemes are discussed and designed to be used in the recovery and purification of dimethyl carbonate from the co-product residual liquid, which contain methanol, dimethyl carbonate and methyl formate etc. in coal-to-ethylene glycol plant, to obtain high purity (over 99.9%) DMC product. Those three process schemes are suitable for feeding DMC composition lower than high pressure azeotropic composition, higher than normal pressure azeotropic composition and more than 90% DMC content, respectively, in which the lower energy consumption and high DMC purity can be achieved.

To reveal the evaporation characteristics of small water droplets sessile on non-horizontal surfaces, this paper constructed a comprehensive 3D model, including diffusion, evaporative cooling, and natural convection in the gas domain, for the investigation of the evaporation processes of droplets evaporating on horizontal and vertical substrates under the assumption that the model was quasi-steady. By analyzing the change of temperature distribution, the local evaporation flux distribution at the gas-liquid interface, and the change of total evaporation rate, the influence of the superheat of the substrate and the change of gravity to the total evaporation performance were studied. The results showed that the temperature distribution at the interface of droplets evaporating on vertical substrates presented obvious asymmetry, which was contrary to the symmetrical distribution on horizontal substrates. The asymmetry amplified as the superheating of substrate increased and the minimum-temperature point appeared on the one side of the droplet rather than the apex. Besides, the local evaporation flux distribution on the horizontal substrate was symmetrical and the distributions of different sections were almost the same. While, the evaporation flux distribution on a vertical substrate presented apparent asymmetry and was anisotropic cross-sections due to the result of a change of natural convection in the gas domain caused by the gravity change. Compared to horizontal substrates, the total evaporation rates of droplets evaporating on vertical substrates were higher and the total evaporation times were shorter. Finally, the inner flow of the droplet turns from symmetrical double-vortex flow to the asymmetrical single-vortex circulation flow as the substrate turns from horizontal to vertical. The velocity of single-vortex flow was remarkably bigger than that of double-vortex flow and the velocity magnitude increased as the superheating of substrate rose. It was the single-vortex circulation flow inside the droplet that made the temperature distribution at the interface asymmetrical and drove the minimum-temperature point to deviate from the apex and appear on the one side of the droplet.

The recovery of electronic-grade hydrogen fluoride (HF) gas has good economic, environmental and social benefits, and adsorption is one of the most promising methods for its recycling. However, the problem of high energy requirement limits its further development, and the research on the energy conservation and consumption reduction has not been conducted for this process. The performance of the adsorption cycle was studied by calculating a series of indexes such as energy consumption. The adsorption equilibrium isotherm data of HF was calculated by molecular simulation technique. The numerical model of temperature swing adsorption (TSA) was established, which was used to determine the index parameters of evaluation cycle efficiency. The operating parameters such as adsorption temperature and pressure were changed to analyze the changing trends of the cycle indicators such as energy consumption and energy efficiency, so as to explore the direction of reducing energy consumption and improving efficiency. The results showed that when the adsorption temperature decreased from 298K to 288K, the recycling energy consumption reduced from 14.0912MJ/kg to 3.1173MJ/kg HF, and the energy utilization efficiency increased from 0.02 to 0.0953. Moreover, as the desorption temperature increased from 340K to 350K, the recycling energy consumption reduced from14.0912MJ/kg to 12.0037MJ/kg HF, and the energy utilization efficiency increased from 0.02 to 0.0247. These results indicated that reducing the adsorption temperature is more significant in reducing energy consumption and improving energy efficiency. In addition, the following conclusions were also obtained: increasing intake concentration had positive effects on all the indexes while the increase of adsorption pressure only had a great influence on the recovery rate. The temperature difference between hot and cold sources and operation only affected the yield.

To study the influence of broken membrane pressure on combustible gas explosion characteristics, the large eddy simulation (LES) and Zimont combustion model were used to simulate the combustion process of H₂/air premixed gas under different broken membrane pressure conditions at the vent (0.1MPa, 0.3MPa, 0.5MPa, 0.7MPa). The results showed that there were three peaks and two troughs in the flame propagation velocity curve under each working condition in the pipeline with a large aspect ratio due to wall effect, acoustic shock, and flame instability. Except for the working condition with the broken membrane pressure of 0.1MPa, the opening of the vent produced a deceleration effect, which made the flame propagation speed lower than that of the closed pipeline in each condition. The pressure in the pipeline of each working condition suggested a general downward trend after the opening of the vent, and the lower the broken membrane pressure, the smaller the pressure peak. Compared with the closed pipeline, the rate of pressure rises of each working condition decreased, and the intensity of the explosion decreased. When the broken membrane pressure was 0.3MPa, the pressure rise rate dropped to the largest extent, and the venting effect was the best.

Silicon (Si) is regarded as one of the most potential substitutes for the existing commercial graphite anode materials. However, the volume change of silicon-based materials during the charging and discharging process has seriously affected the electrochemical performance and lifespan of the battery. Therefore, how to effectively overcome the volume effect for the improvement of the electrochemical performance has become an urgent problem. In this paper, recent progress in the modification of silicon-based anode is reviewed as the following three aspects: physical method, chemical method, and the combination of various methods. Different preparation methods and processes are introduced, classified, compared, and analyzed, meanwhile, their advantages and disadvantages are also summarized. In the end, the future research and development of high-performance silicon-based anode are prospected to provide references for the optimization of silicon-based anode performance and exploration of new preparation methods.

The properties of wax deposits significantly impact crude oil pipeline pigging operation, and this topic has become a hotspot in flow assurance research. This paper reviews the recent research progress on the radial properties of wax deposits in crude oil pipelines and compares the advantages and disadvantages of the current experimental methods. The understanding and conclusions of the radial properties of wax deposits were expounded from four aspects: composition, wax precipitation characteristics, macroscopic appearance and microstructure, as well as mechanical properties. Meanwhile, the intrinsic influencing factors and acting mechanism were analyzed. The theoretical foundations and shortcomings of wax molecular diffusion coefficient and radial wax content distribution models were evaluated. Finally, the future research directions were presented: mechanical sampling device with higher accuracy needs to be developed, the influencing mechanism and quantitative relation between the macroscopic rheological properties of wax deposits and their microstructure characteristics need to be revealed, and predictive models of radial properties of wax deposits considering the diffusion kinetics of wax molecules in the porous media need to be established.

Co-pyrolysis of coal and biomass is an important way to achieve efficient and clean utilization of coal. Co-pyrolysis can alleviate the pollution caused by coal pyrolysis and limit the disadvantages of low energy density and unbalanced seasonal supply during individual utilization of biomass, so that both of the efficiency of coal conversion and the oil quality are improved. This article reviews recent researches on co-pyrolysis of coal and biomass from the aspects of influencing factors, research methods and the interaction of components during co-pyrolysis process. The effects of biomass types, pyrolysis process parameters and pyrolysis reactor types on the co-pyrolysis process of coal and biomass are summarized, while the interaction between coal and biomass and the catalysis of alkali in volatile matter are also pointed out. Furthermore, development directions to further understand the interaction mechanism between coal and biomass, and improve the efficiency of co-pyrolysis are discussed.

Based on the production needs of low-sulfur heavy marine fuel and the background of the transformation and upgrading of the refinery to maximize the raw materials production for reforming and ethylene cracking, this paper analyzes the economics of two heavy oil processing schemes of ebullating bed and slurry bed, which are typically used in the production of low-sulfur ship fuel in refining and chemical integrated enterprises, in terms of product distribution, product properties and subsequent processing routes. The results show that, compared with the slurry bed hydrogenation scheme, the fluidized bed scheme gives lower residue hydrogenation conversion rate, dry gas yield, and nitrogen content in various distillates. In addition, the ebullating bed residue hydrogenation scheme can directly produce low-sulfur ship fuel without waste residue, consume less hydrogen, and produce more jet fuel, naphtha and aromatics. When the crude oil price was 50 USD, the ebullating bed scheme has a gross profit after excise tax deduction of 1.613×10⁹ CNY more than the slurry bed program. It can be seen that for the refining and chemical enterprises with low-sulfur ship fuel production needs, the ebullating bed heavy oil processing route is more economically competitive.

China's coking coal resources are scarce and unevenly distributed. However, the low-grade coal in China is rich in reserves, low in price, and has the characteristics of low ash and low sulfur, near-zero caking index. Catalytic hydrogenation is an effective method to improve the caking property of low-grade coal. In this paper, the catalytic hydrogenation of long-flame coal was carried out, and elemental analysis, infrared analysis, electron paramagnetic resonance analysis, and reaction hydrogen consumption calculation were performed for the raw coal and modified coal to study the role of catalyst and the hydrogen transport mechanism. The results indicated that the caking property of long-flame coal was significantly enhanced, which could partially replace coking coal in the coking process. Hydrogenation can remove part of the oxygen-containing functional groups and alkyl side chains in the long-flame coal, and reduce the degree of crosslinking of coal molecules. The main function of the catalyst is to activate hydrogen, and secondly to promote the depolymerization of coal molecules and promote the hydrogen transport of tetralin to coal. In the presence of a catalyst, the dominant hydrogen transport path of the catalytic hydrogenation reaction is directly from hydrogen to coal molecules instead of from hydrogen donor solvent to coal.

China is now vigorously developing coal-to-SNG process for clean energy supply. However, recent studies reveal that this process suffers from high energy consumption and greenhouse gas emissions. An effective way to solve it is to increase the plantwide energy efficiency by Total Site Heat Integration. The total site profile of coal-to-SNG reveals that the low temperature waste heat recovery and the heat integration between coal gasification unit and water gas shift unit could provide considerable energy savings. The total site analysis method was used to target the maximum heat recovery and the optimal site utility system. The results showed that the site utility consumption decreased from 1.26t/kNm³ to 1.07t/kNm³ SNG and the plantwide energy efficiency was increased from 57.2% to 59.6%. On the other hand, the CO₂ emission decreased from 5.02t to 4.66t CO₂ per kNm³ SNG. The water consumption of the integrated process decreased around 33.4% compared to that of the conventional process. Unit production cost decreased from 1.65 CNY/Nm³ SNG to 1.59 CNY/Nm³ SNG. Thus, an annual production cost of 120 million CNY could be saved for an annual production of 2×10⁹ m³ natural gas.

Unconverted oil from ebullated bed hydrogenation (UCO) has significant advantages as coking feedstock for preparation of low sulfur petroleum coke. The model was established to forecast the coking product yield and quality of UCO based on multiple stepwise regression method, and the differences of coke rule between UCO and residue were analyzed. The results indicated that the yields of coke and liquid product were single variable linear function of CCR content of UCO in the delayed coking process of UCO. Meanwhile, the sulfur content of liquid product was the single variable linear function of sulfur content of UCO. However, there had bivariate function between the sulfur content of coke and properties of UCO, and the two variables were sulfur and CCR content of UCO. The model prediction effect was good, and the average relative error was less than 2.0%. Compared with coking rule of residue, the sulfur content of coke in UCO coking process was relatively higher, basically remaining at around 60%, and coking tendency of UCO was higher. Based on the results of multiple stepwise regression, and using linear programming method, the linear programming diagram was drawn to optimize the UCO properties for preparation of low sulfur petroleum coke, which could be used to attain value range of UCO properties under the different demand for petroleum coke yield and sulfur content of coke.

In recent years, the influence of structural properties such as valence, facet and micromorphology on the catalytic performance of Cu-based catalysts has been extensively studied, and highly selective electrochemical reduction of CO₂ to high value-added multi-carbon (C₂₊) products over Cu-based catalysts has achieved great progress. This review provides an overview of the research progress in structured Cu-based catalysts for electrochemical reduction of CO₂ to C₂₊ products in the past five years, and analyzes the structure-activity relationship among the catalytic activity and reaction selectivity and the presence of mixed valence states, high-active facets and rich grain boundaries on the catalyst surface, as well as the structures with abundant confine spaces such as nanowire arrays, nanodendrites and nanoporous structures. The new trend in CO₂ electrochemical reduction is further proposed, that is, to take full advantage of the synergistic effect of various structural factors, to in situ prepare nanoporous Cu-based catalysts with mixed valence states and rich grain boundaries, and to apply flow cell to efficiently and continuously reduce CO₂ to C₂₊ products.

As a typical post-graphene two-dimensional nanomaterial, MoS₂ has been extensively studied in recent years due to its excellent performance and superior chemical and thermal stability. The structure-performance relationship and reaction mechanism of its catalytic active sites are the current research hotspots. This article introduces the structural characteristics of MoS₂ as well as the distribution of active sites, and focuses on the analysis of the construction methods of MoS₂ active sites in recent years, including the modification of the MoS₂ through dimensions reduction, control of crystal phase, design of special morphology and amorphization. Meanwhile, the synergetic modification of MoS₂ can be achieved by means of atom doping and defect engineering. By discussing the catalytic performance and the corresponding modification reaction mechanism, it is shown that the catalytic performance of MoS₂ can effectively enhanced by using these methods. Finally, the current challenges and research directions are analyzed and summarized, and it is pointed out that to build active sites homogeneously dispersed on MoS₂ and balancing the structure-performance relationship between catalytic activity and stability of the active sites should be the focus of future research on MoS₂ in the field of photoelectrocatalysis.

The efficient and green catalytic conversion of 5-hydroxymethylfurfural (HMF) into higher value-added 2,5-furandicarboxylic acid (FDCA) has become a research hotspot in the field of biomass energy conversion. The basic carrier supported precious metal catalysts for the base-free aerobic oxidation of HMF to FDCA have been extensively studied, and a series of results have been achieved. In this paper, the latest developments of hydrotalcite, hydroxyapatite, carbon materials, metal oxides and other carrier-supported noble metal catalysts for the base-free aerobic oxidation of HMF to FDCA are reviewed. The structure, properties, catalytic reaction parameters and catalytic activity for different catalysts are introduced. Moreover, the structure-activity relationship and the catalytic reaction mechanism are discussed. Finally, the future directions of the design and development of supported noble metal catalysts and mechanism exploration are pointed out for converting HMF to FDCA.

Hydrogen production from ethanol has the advantages of environmental friendliness, cleanliness, and sustainability. The key to this technology is the appropriate catalyst. Compared with noble metal catalysts, the Ni-based and Co-based catalysts have advantages of low cost and high activity and have become a research hotspot in recent years. However, there are still some problems in the process of ethanol steam reforming with the Ni-based and Co-based catalysts, such as poor stability, low catalytic activity at low temperature and short life time. Therefore, this paper firstly introduces the mechanism of hydrogen production from ethanol. Based on the types of support and the alloying modification of active catalyst nanoparticles, we then reviews the recent research results of Ni-based and Co-based catalysts for hydrogen production from ethanol steam reforming. Thereafter the methods to improve the performance of the catalysts are summarized. Finally, the future development direction of Ni-based and Co-based catalysts is prospected, which provides ideas for the preparation of Ni-based and Co-based catalysts with small particle size, high low-temperature catalytic activity and good stability.

Metal-zeolite bifunctional catalysts have two kinds of active sites, which is suitable for promoting the catalytic efficiency of complex reactions such as alkane isomerization. Based on our understanding of the mechanisms of hydrogenation/dehydrogenation on metal sites and carbon chain isomerization on acid sites, several typical cases in frontier researches and the study strategies were summarized in order to provide fundamental insight for the research and development of novel efficient catalysts for alkane isomerization. Regarding the control of the proximity of bifunctional sites, the spatial distribution control strategies of metals, zeolites and binders are introduced, and it is pointed out that the appropriate distance between the two sites is beneficial to the diffusion of olefin intermediates. For improving the utilization of acid sites, the hierarchically structured zeolites with micro-meso porous structure or short diffusion distance are introduced, and it is pointed out that the enhanced diffusion and mass transfer can help to inhibit the side reaction of olefin cracking. To improve the utilization of metal sites, the highly dispersion method of precious metals is introduced, and the strategy of using light transition metals to replace precious metals is briefly described. In view of the future development, it is necessary to further study the proximity of bifunctional sites in the forming process of industrial catalysts, to improve the utilization of acid sites and metal sites, and to reduce the cost of precious metals in catalysts.

The preparation of titanate nanotubes by hydrothermal method is regarded as a simple, convenient and mild technique, and is suitable for large-scale production, which had received a lot of attention. Titanate nanotubes prepared by this method have unique features, including open-ended structure, large specific surface area, good stability and ion-exchangeable ability. In this paper, the formation mechanism of TNTs was introduced briefly. The influence of various preparation conditions such as precursor materials, hydrothermal conditions, post-treatment on the structure of the TNTs were reviewed in detail. Recent advances in the applications of TNTs as supports, photocatalysts, acid catalysts, and adsorbents were also reviewed. TNTs materials with different structures and properties can be obtained by adjusting both hydrothermal conditions and post-treatment process. In order to improve the performance of TNTs, the modified TNTs materials can be obtained by doping, ion exchange method, surface modification and other methods. Improving the efficiency of hydrothermal synthesis, optimizing chemical modification strategies and obtaining TNTs with different properties were the main development trends in the future.

Porous carbon materials with larger specific surface area and more developed pore structure have become a key material for adsorption of toxic and harmful gases, and also have drawn wide attention on many fields, such as environment, chemical industry, military chemistry and so on. The adsorption performance of toxic and harmful gases on porous carbon materials is influenced by the competitive adsorption behavior of water molecules in atmosphere. The adsorption behavior of water molecules on porous carbon materials is the basis of the adsorption and separation of toxic and harmful gases in complex environment, which has important guiding significance of improving the composition of surface functional groups and pore structure of porous carbon materials. Thus, this paper reviewed the adsorption mechanism, process and influencing factors of water molecules on porous carbon materials, discussed the potential for water molecules as tracer molecules for structural characterization of porous carbon materials, and prospected the future research direction of adsorption theory and the application foreground to guide the design of new adsorption materials.

Electrode materials play a vital role on the performance of supercapacitors. Hence, it is important to develop novel electrode materials with excellent properties. NiCo₂O₄ has the advantages of easy synthesis, low cost, abundant natural resources and high theoretical capacitance, and has been widely studied as novel electrode materials for supercapacitors. However, the low conductivity, small specific surface area and poor electrochemical stability of NiCo₂O₄ has seriously limited its application. In this review, we present a brief description of the structure of NiCo₂O₄ and the energy storage mechanism of supercapacitors. Furthermore, we review several synthetic methods of NiCo₂O₄ and current modification researches, including morphology modification, composite modification and imported defects. In the future, the research should focus on the environmental friendly and efficient preparation method, improving the electrochemical performance by doping or defects, increasing the working voltage window and exploring suitable electrolytes.

Due to its unique electrical conductivity and electrochemical properties, polyaniline has become an important material for bipolar plate protection along with the development of fuel cells in recent years. However, the long-term corrosion resistance of the polyaniline coating under the high temperature and strong acid working environment of the proton exchange membrane fuel cell still cannot meet the requirements, which limits its large-scale application. This article reviews the latest research progress on the application of polyaniline-based coatings on bipolar plates for proton exchange membrane fuel cells, including the polyaniline coating modified by doping and copolymerization, and the polyaniline-based composite coating with the introduction of polymer materials and nanomaterials. The electrochemical test and performance results of various typical coatings are analyzed, and the corrosion resistance mechanism of polyaniline-based composite coatings is discussed. Finally, the current problems in the research of polyaniline-based coatings are summarized, and the direction of research and development is prospected. It is pointed out that the test standard should be consistent which has great significance for material performance evaluation and commercial application. Furthermore, the research on nano-material composite coatings should be strengthened in the future and the analysis of the coating mechanism in depth should be based on in-situ observation and characterization technology.

Titanium dioxide (TiO₂) can generate active groups with strong oxidation properties under light activation, and activated carbon (AC) has good adsorption performance. TiO₂/AC composite materials prepared by supporting TiO₂ on AC can remove most refractory organic pollutants effectively; Consequently, it has prospective applications in environmental purification. In this paper, we review the research status of TiO₂/AC composites, and introduce three major TiO₂/AC composite preparation technologies, including the sol-gel method, solvent-thermal method, and microwave synthesis method. Materials prepared using the sol-gel method are stable, the solvent-thermal method has mild preparation conditions, and the microwave synthesis method has relatively short cycle. We also introduce current TiO₂ modification methods, such as ion doping, semiconductor composite, and noble metal deposition, which are aimed at addressing low visible light absorption and low quantum utilization. In addition, we summarize the applications of TiO₂/AC composite material in the removal of refractory organic pollutants (e.g., dye wastewater, drugs, phenols, and volatile organic compounds). Finally, we outline the challenges encountered in modification attempts and during the application of TiO₂/AC composite materials, and their potential solutions. This review could provide a reference for further comprehensive investigations on TiO₂/AC composite materials and facilitate their large-scale industrial production and application.

In this study, the solution blending method was used to explore the preparation of phytic acid/gelatin composite films by adding different proportions of phytic acid. The effect of different phytic acid content on the crystalline structure, microscopic morphology, transparency, swelling and mechanical strength of the composite film was tested, and then the structure regulation and performance improvement effect of phytic acid on the gelatin film were analyzed and explored. The results showed that compared with pure gelatin film, phytic acid had obvious crosslinking modification effect on gelatin. The composite film had a compact and uniform internal structure. Phytic acid inhibited the self-crystallization behavior of gelatin through the interaction of polar groups and reduced the crystallinity of the composite film. As the content of phytic acid increased, the visible light transmittance of the composite film decreased. The swelling rate changes indicated that the structural reorganization of phytic acid and gelatin can effectively block the penetration of water molecules. The mechanical strength of the composite film was increasing with the addition of phytic acid. When the mass fraction of phytic acid reached 10%, the tensile strength of the phytic acid/gelatin composite film was 61.57MPa, which was about 20% higher than that of pure gelatin (50MPa). However, it had no obvious effect on elongation at break.

Proton exchange membrane (PEM) as the key component of a proton exchange membrane fuel cell is required to selectively and fast transport protons. The porous organic cage has a high specific surface area, good chemical stability, high water absorption and a three-dimensional connected proton transport path, which is expected to improve the proton conductivity of PEM. In this work, the porous organic cage 3 (CC3) molecules were immobilized on the surface of polyacrylonitrile (PAN) nanofibers by in situ growth method, and then a hybrid proton exchange membrane was prepared by impregnation with Nafion membrane solution. In this work, a hybrid proton exchange membrane was prepared by immobilizing CC3 onto the surface of PAN nanofibers followed by impregnation with Nafion membrane. The results of structure and performance studies showed that CC3 was successfully immobilized on the surface of PAN nanofibers by step reaction, and the specific surface area was thus increased to 113.6m²/g from 9.57m²/g. The introduction of CC3/PAN into the composite membrane significantly improved the thermal stability, water absorption and alcohol resistance of CC3/PAN-Nafion. Among them, the proton conductivity of CC3/PAN-Nafion12 can reach 0.165S/cm at 100% RH and 80℃, which was 100% higher than Nafion.

The polytetrafluoroethylene (PTFE) is widely used as a container for microwave chemical reactions because it is transmitting material with relatively low complex dielectric constant. The dielectric properties and transmitting properties of transmitting materials have an important influence on the rate and effect of microwave chemical reactions. In this article, firstly, the complex dielectric constant of PTFE in the range of 23—250℃ was measured by the resonant cavity perturbation method and the temperature characteristic of the dielectric properties of the material was analyzed. Secondly, based on the principle of electromagnetic wave transmission, the power transmission coefficient (T²) of the material affected by different factors was calculated and the transmission performance of the material were analyzed. The research showed that with the increase of temperature, the dielectric constant of PTFE gradually decreased and the loss tangent gradually increased, but the magnitude of the two changes were small. There was a Brewster angle in the transverse magnetic field (TM). When microwaves were incident at this angle of incidence, total transmission occurred. The T² in the TM polarization mode firstly increased and then decreased with the increase of the incident angle. The T² in the transverse electric field (TE) decreased with the increase of the incident angle. The overall transmission performance in TM polarization mode was better than TE polarization. As the wall thickness of the container increased, the transmission performance fluctuated and there were maximum and minimum values. Within the same container wall thickness range (0—0.1m), the wall thickness range corresponding to high transmission performance at 2450MHz frequency was more than 915MHz. The research also showed that when the incident angle of microwave was small, the T² of PTFE always remained between 0.87 and 0.99 and the transmission performance was better. Finally, this article also gave the preferred wall thickness of PTFE for reference in practical applications when microwaves were incident at different frequencies.

MoS₂/ZnO hetero-nanocomposites were successfully prepared by physical stripping and nanoparticles shearing on the basis of ZnO nanosheets previously prepared by solvothermal method. The structure, morphology, photocatalytic and optical properties of the as-prepared products were characterized using scanning electron microscope, transmission electron microscope, energy dispersive X-ray spectroscopy, X-ray diffractionmeter, Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy and photoluminescence spectrum. The results showed that MoS₂/ZnO composite can be obtained effectively by physical stripping and shearing. The Raman intensity of 378 cm^-1 and 400 cm^-1 of MoS₂ remarkably increased as MoS₂ was combined in ZnO, but the difference between wavenumbers of the two Raman peaks decreased. With decreasing content of MoS₂, the intensity of these two Raman peaks became strong, and the wave number difference between the two Raman peaks decreased accordingly. It can be explained that the physical shearing effect of ZnO nanoparticles on the MoS₂ was significant as MoS₂ at low concentration with the result that MoS₂ showed a good dispersion and a small thickness. MoS₂ concentration had obvious modulation on MoS₂/ZnO luminescence and significantly enhanced the absorption of the composite in the visible region. Increasing MoS₂ content, the visible luminescence intensity decreased rapidly and the ultraviolet luminescence peak appeared blue shift obviously. The degradation rate of phenol by pure ZnO was as high as 90%, while that of MoS₂/ZnO composite was 100%, and the final degradation rate of phenol by the composite was obviously higher than that of pure zinc oxide.

Lauric acid (LA), myristic acid (MA), palmitic acid (PA) and stearic acid (SA) were used as the main phase change materials with different particle sized activated carbon (size of AC were 75μm, 48μm, 45μm and 38μm) as the framework. All the composite materials were prepared by melt-blending method. Graphite was added to enhance the electrical conductivity of the composite phase change materials. The density, leakage rate, latent heat, thermal conductivity and electric conductivity of the composite phase change materials were studied systematically. The results showed that the mass fraction of AC added in fatty acid (FA) decreased with the decrease of particle size by 16%, 12%, 9% and 7%, respectively. AC had the best adsorption effect on MA and the worst adsorption effect on SA. The leakage rate of AC/FA decreased with the increase of AC additive amount and forming pressure, while the density was opposite. The maximum multiples of improvement of thermal conductivity of AC/FA over pure FA were 7.6 times, 10.7 times, 5.1 times and 5.1 times, respectively. AC/FA resistivity decreased with increasing pressure and graphite content. After adding 10% graphite the latent heat of the graphite composite phase change materials was dropped from 52.88—141.9J/g to 36.4—106.4J/g, but the resistivity was reduced from tens of thousands to less than 30.70Ω·cm, and thus the conductive performance was improved.

Phase change materials with excellent performance are very important for the application of natural cooling source in building air conditioning. Composite phase change materials CA-LAFe₂O₃/EG was prepared using the CA-LA eutectic acid as phase change materials, nano-Fe₂O₃ as additive, and expanded graphite(EG) as matrix materials by chemical dispersion, ultrasonic oscillation and physical adsorption. The properties of the materials were characterized. The results showed that it was better mixing uniformity with CA-LA when the mass fraction of nano-Fe₂O₃ was 0.8%, which eliminated the supercooling of CA-LA. When the mass fraction of EG was 5.88%, it had a good adsorption on CA-LA Fe₂O₃(0.8%). FTIR spectrum revealed that there was no chemical reaction in CA-LAFe₂O₃/EG. The crystallization process showed that adding nano-Fe₂O₃ particles and EG can accelerate the cooling and crystallization process. The cooling and crystallization time was reduced 39.4% by adding only nano-Fe₂O₃ particles and 78.2% by adding nano-Fe₂O₃ and EG, which was conducive to the cold storage process. DSC results indicated that the enthalpy of CA-LAFe₂O₃(0.8%)/EG (5.88%)/EG was 124.70kJ/kg, which was 3.4% lower than that of pure CA-LA. The oneset melting temperature was 18.66℃ and the oneset crystallization temperature was 19.87℃. Compared with CA-LA the temperature range during melting and crystallization was increased and the thermal conductivity of the material was enhanced. The thermal response of shape stabilized composite phase change materials was affected by the anisotropy of expanded graphite and its thermal response was related to the compression direction. The temperature response speed in the tangential direction of compression was far greater than that in the normal direction. The anisotropy of the materials should be considered in the design of phase change energy storage heat exchangers.

In this paper, the phase structure and phase distribution of polystyrene/poly(methyl methacrylate)(PS/PMMA) blend with PS-b-PMMA block copolymer as the compatibilizer were studied by Raman spectroscopy imaging. The experimental results showed that Raman Mapping technology can not only provide accurate distribution of chemical components, but also give the molecular fingerprint spectra of dispersed phase, interface phase and continuous phase in the blend system. It is found that the phase structure of the blend system distributed in a “sea-island” form. When PS/PMMA=30/70, the dispersed phase was PS, and the continuous phase was PMMA; when PS/PMMA=50/50, the dispersed phase was PS, and PS also presented in the PMMA continuous phase; when PS/PMMA=70/30, the dispersed phase was PMMA, and the continuous phase was PS. The particle size of the dispersed phase decreased and distributed more uniformly when the block copolymer PS-b-PMMA was added into the PS/PMMA blend. Moreover, the semicompatible blends showed much smaller subphase distributions with less distinct interphase and increased compatibility number (N_c). It revealed that the compatibilizers could enhance the interaction between PS and PMMA, reduce the phase separation degree and improve the compatibility of the blend system.

Three catalysts, NiMo/β, SnNiMo/β and ZnNiMo/β were prepared by incipient-wetness impregnation method with β zeolite as the support. The catalysts were characterized by XRD, NH₃-TPD, H₂-TPR, H₂-TPD and TG-DTG. The results show that the addition of Sn and Zn weaken the acid properties of the catalyst, promoted the interaction between Mo and the support, improved the H₂ adsorption capacity of the catalyst, and reduced the amount of carbon deposition in the reaction process. The three catalysts were evaluated by using reforming C₁₀₊ heavy aromatics. The results show that the addition of Sn and Zn significantly improved the stability and liquid yield, and the catalyst containing Zn had the best heavy aromatics to light aromatics properties.

The cathode material of submicron LiFe_0.05Mn_1.95O₄ single crystal was synthesized by a solid state combustion method. The structure, morphology, phase composition and electrochemical performance of the sample were investigated by XRD, FE-SEM, TEM, XPS and galvanostatic charge and discharge. The results showed that, Fe-doping did not change the cubic crystal structure of spinel LiMn₂O₄, but the crystal surface corresponding to {400} and {440} diffraction peak exhibited a significant selective growth, and the single crystal deciding-angle octahedral grains with the morphologies of {111}, {110} and {100} crystal surface were formed. The LiFe_0.05Mn_1.95O₄ cathode material exhibited better electrochemical performance than the undoped sample of LiMn₂O₄. The initial specific discharge capacities were 114.7mA·h/g and 104.7mA·h/g at 1C and 5C, respectively. The capacity retention was 83.9% at 10C after 1000 cycles. By analyzing the cyclic voltammogram and electrochemical impedance spectroscopy, we found that the Fe-doped sample possessed large lithium ion diffusion coefficient and low apparent activation energy. The spinel structure of the sample's electrode slice was almost unchanged after 1000 cycles at 5C. Appropriate Fe-doping can effectively inhibit the Jahn-Teller effect and the Mn dissolution of spinel LiMn₂O₄ in the process of charge and discharge cycles, and hence improve the capacity retention and structural stability of the material.

Cell immobilization technology, characterized by its high efficiency, simple reaction operation, long-term cell viability, repeatability, good stability and high tolerance, has shown great application potential in the field of biological fermentation industry. In this paper, the research progress of polymer carrier materials, inorganic carrier materials and composite carrier materials in the field of biological fermentation was reviewed. The differences in growth metabolic property between free and immobilized cells in a complex environment, such as low or high pH, toxic substrate and high concentration products were analyzed. In addition, the advantages and applications of new polymer membrane materials (hollow fiber membrane and micro/nano fiber membrane) as carriers in biological fermentation were also described. Finally, the controllability and robustness of the artificial microbial system in biological fermentation were prospected by designing excellent polymer carriers. The results showed that materials as active and tunable components at the interface of living and nonliving matter offer a suitable microenvironment for cells, which will be more widely used in the field of biological fermentation in the future.

The use of microbial cell factories to realize the transformation of raw materials and the synthesis of products is the core of green biological manufacturing. However, the current bio-manufacturing mainly uses sugar-rich grains as the raw material, leading to a controversy of "competing with the people for food". As a result, there is an urgent need to develop non-food raw materials. As a main product of coal chemical industry, methanol has the advantages of abundant sources, low price, and high degree of reduction, indicating that it has the potential to replace food raw materials. Natural methylotrophs have been used to produce single-cell protein and various amino acids from methanol. However, there are many disadvantages such as low theoretic yield and inefficient genetic tool. With the development of synthetic biology, the use of model organisms such as Escherichia coli as chassis cells to construct artificial methylotrophic bacteria and realize the production of methanol to various chemicals has become a research hotspot. In this review, we firstly summarized the construction strategies of a variety of methylotrophic Escherichia coli. Then, the key factors affecting the metabolism of natural pathways and important intermediate metabolites were clarified. Moreover, various methods for optimizing natural methanol metabolic pathways and constructing new artificial pathways were discussed. And we put forward a prospect for the optimization of methanol utilization by engineering strains.

Membrane distillation (MD) is a newly developing desalination technology. However, actual water contains complex composition such as surfactants, oils, easy scaling salts and organic solvents. Therefore, the traditional hydrophobic membrane is easily fouled or wetted during a long-term operation, which results in membrane flux or salt rejection rate decrease. The characteristics and types of membrane fouling and wetting were introduced in this paper. The differences and relations between fouling and wetting were also analyzed. The monitoring and predicting methods were briefly described during membrane fouling and wetting process. Finally, the research progress in preventing fouling and wetting was mainly introduced. By considering the interaction between pollutants and hydrophobic membrane, the researchers usually modified the surface of hydrophobic membrane to develop omniphobic and Janus composite membranes. Those novel membrane surfaces could avoid the adsorption of pollutants and inhibit wetting. In recent years, pervaporation was also studied in desalination to control membrane fouling and wetting, in which dense hydrophilic membrane was adapted. In addition, feed pretreatment could significantly delay fouling and wetting, such as coagulation/precipitation, boiling, membrane filtration, pH control, etc. Various feeding modes, external magnetic field and microwave radiation were investigated to control the local hydrodynamics boundary condition near the membrane surface and to reduce the adhesion of pollutants. The membrane performance could be recovered after proper post-treatment. Finally, the research direction on membrane fouling and wetting in MD process were pointed out.

Ammonia gas (NH₃), as a harmful basic gas, not only pollutes the environment but also causes irreversible damages to human beings. In electronic information, energy, and other related industries, a trace amount of NH₃ can affect product quality and reduce process performance. Therefore, deep removal of NH₃ has important industrial significance. In this review, the status of deep removal of NH₃ is reviewed, and the separation performance of various materials, including ionic liquids, deep eutectic solvents, modified activated carbon, molecular sieves, modified alumina, metal salts, metal-organic frameworks, porous organic polymers, covalent organic frameworks, graphite oxide, and Prussian blue analogs are discussed. The technological characteristics for deep removal of NH₃ as well as the performance requirements for deamination materials are summarized. The challenges in this field are briefly analyzed with suggestions put forward for future development.

In recent years, direct interspecific electron transport has been found to be an important electron transport pathway in anaerobic processes. Moreover, the addition of magnetic materials makes it easier to drive such electron transfer. Therefore, in this paper, based on literature research at home and abroad, magnetic materials are divided into single magnetic materials and composite magnetic materials. The application of the zero-valent iron, metal oxides (FeO, Fe₂O₃, Fe₃O₄) and magnetic carbon materials enhanced anaerobic technology in waste water treatment, which has a positive role in wastewater degradation rate, methane yield, volatile fatty acid, extracellular polymers, enzyme activity, etc., and the influence factors (temperature, pH, concentration of pollutants, the size of the magnetic material and additive quantity, etc.) are introduced. The mechanism and the existing deficiency in different magnetic material induced direct interspecific electron transfer are analyzed, and the technical advantages of magnetic carbon materials are emphasized. The research direction of direct interspecific electron transfer induced by magnetic carbon materials is put forward, and the construction of anaerobic microbial conductive system is the important direction of its future development.

As a by-product of the wastewater treatment process, the efficient treatment and disposal of activated sludge are one of the difficult problems in the field of environmental protection. The conversion of activated sludge into biochar through high-temperature pyrolysis is an effective way. Sludge biochar can be used as an adsorbent to remove pollutants, meanwhile, it is a novel catalyst, which can efficiently catalyze advanced oxidation process to degrade organic pollutants in water. In this paper, the research progress on the degradation of organic pollutants by sludge biochar in the field of advanced oxidation technology was reviewed, especially in the catalytic process of persulfate (PS), hydrogen peroxide (H₂O₂), ozone (O₃), and photocatalysis. The key active sites and catalytic mechanisms of sludge biochar were revealed by the discussion of the surface functional groups, doping modified heteroatoms, loading transition metals and their oxides, and coupling with other technologies for the degradation of organic pollutants. Finally, the main problems and future development direction in this field are put forward, which provides an important reference for further realizing high value-added resource utilization of sludge biochar.

Complex working conditions is often encountered in petroleum exploitation, gathering and processing. Natural surfactants are mixed with artificial emulsifier and nano-micron solid particles to form petroleum pickering emulsion, which makes the oil-water system in a stable state of O/W, W/O or multiple emulsification. Oil-water emulsion is the main product of water flood recovery, and its efficient demulsification is a common demand in the petroleum industry chain. At present, petroleum industry still adopts the demulsification method for common oil-water emulsion. But for the complex oil-water emulsion, the oxidative demulsification aiming at removing the film-forming emulsifier is better than the traditional demulsification. In view of this, based on the efficient oxidative demulsification mechanism, this paper introduced the characteristics and negative effects of petroleum pickering emulsion. Compared with the traditional chemical demulsification method without oxidation reaction, the demulsification progress of molecular oxidation, photocatalytic oxidation and electrochemical oxidation for oil-water emulsions with different sources and characteristics were reviewed. For each method, the process mechanism, application examples, advantages and disadvantages were analyzed in detail. Finally the limitations of these oxidation methods were summarized and prospected to realize the accurate demulsification of petroleum pickering emulsion in the future.

The effects of different bases and their addition amount on the reductive dechlorination of 4-chlorophenol (4-CP) over Raney Ni in 50% ethanol-water (50/50, v/v) were studied. Compared to weak inorganic bases, strong inorganic bases (NaOH and KOH) and triethylamine (Et₃N) were more favorable to the Raney Ni-catalyzed reductive dechlorination reaction. Moreover, Raney Ni exhibited high catalytic activity when n(NaOH/Et₃N)∶n(4-CP) was 1.1—2.2, and the complete reductive dechlorination of 4-CP could be achieved within 30min. Based on the above studies, the catalytic system of Raney Ni-50% ethanol-water (50/50, v/v)-NaOH was developed, and applied to investigate the effects of different substituents on the reductive dechlorination of chlorinated aromatic compounds. The results showed that Raney Ni exhibited high selectivity for reductive dechlorination of 4-CP and 4-chloroaniline (4-CA). Furthermore, the catalytic system was applied to reductive dechlorination of industrial hazardous waste with high concentration chlorophenols. It was found that the chlorinated organic pollutants in industrial hazardous waste could be completely dechlorinated within 240min, and Raney Ni could be reused at least 5 times. Thus, the catalytic system showed excellent application potential for reductive dechlorination of industrial hazardous waste with high concentration chlorophenols because of its high efficiency and complete degradation ability.

In order to solve the problems of high acid consumption, low acid utilization rate and the difficulty in separating aluminum and iron during their industrial extraction from coal gangue(CG), low-temperature neutralization-pressure acid leaching is adopted for the first time to achieve high-efficient extraction of aluminum and iron from the CG from Panzhou, Guizhou province. The optimal process conditions for the room temperature neutralization process are as follow: the acid is 20% of the theoretical consumption, the leaching time is 120min, and the mass ratio of sulfuric acid solution to solid is 3∶1. With the neutralized slag as raw material, the optimal process conditions for the pressurized acid leaching process are as follow: leaching time of 120min, leaching temperature of 150℃, and the mass ratio of sulfuric acid solution to solid of 3.5∶1 with the theoretical acid consumption of CG. Under the aforementioned conditions, the leaching rates of aluminum and iron were 95.77%, 98.37% respectively, and the contents of silicon and titanium in acid residue ash were 90.2%, 9.18% respectively. The fresh coal gangue was neutralized with the recycled acid leaching solution, yielding the concentrations of aluminum and iron in the extract solution of 62.20g/L, 57.95g/L respectively. Compared with the conventional acid leaching process, the acid consumption by the two-step process is lower, and the acid utilization efficiency is higher. Through the characterizations of the CG and slag by X-ray diffractometer (XRD), Fourier infrared spectrometer (FTIR) and Scanning electron microscope (SEM), the mechanism of carbonic acid leaching process in gangue was preliminarily analyzed. This work provides a new route and theoretical support for the industrial extraction of aluminum and iron from CG.

The content of lignin and alkaline salt in the pretreatment solution of corn straw obtained by high temperature alkaline salt treatment was high. In order to reuse the pretreatment solution containing salt, soluble lignin should be removed. In this experiment, a lignin-degrading strain CCZU-WJ6 was screened and isolated from rotten wood and was identified as Achromobacter sp. by morphological observation and 16S rDNA sequence analysis. The activities of enzymes related to lignin degradation in CCZU-WJ6, the growth trend of CCZU-WJ6 in corn straw pretreatment solution, COD removal rate and lignin degradation rate of the pretreatment solution were measured. GC-MS and FTIR were used to detect the changes of components and chemical bonds in the pretreatment solution. Through single-factor experiment, the optimal conditions for degradation of the pretreatment solution by CCZU-WJ6 were determined as pH 7.0, temperature 30℃, dilution factor 10 times, and inoculation amount 0.5g/mL. After 6 days of treatment, the removal rate of COD and the degradation rate of lignin were 40.9% and 32.1%, respectively. The activities of lignin peroxidase and manganese peroxidase secreted by CCZU-WJ6 were 215.5U/L and 200.1U/L, respectively. CCZU-WJ6 can destroy the benzene ring structure, ether bond and C＝O bond in the lignin structure, and the degradation products contained guaiacol and p-coumaric acid, which inferred that the degradation pathways are β-aryl ether metabolic pathway and ferulic acid metabolic pathway. CCZU-WJ6 can be used to degrade industrial wastewater containing lignin and has broad prospects in industrial applications.

With rice husk as silicon source, silica was firstly prepared by the direct calcination method, and then the Fe₂O₃/SiO₂ catalyst was prepared by co-impregnation method with the silica as the carrier. As a comparison, the Fe₂O₃/C-SiO₂ catalyst supported on commercial silica was prepared by the same method. Both catalysts were used in catalyzing H₂O₂ to pre-oxidize NO. The effects of different operating conditions (loading, catalysis temperature, vaporization temperature of H₂O₂, flow rate of H₂O₂ and vapor concentration) on the pre-oxidation of NO were systematically investigated. In addition, the physicochemical properties of the catalysts were characterized and attempts were made to correlate them with their catalytic performance. The experimental results indicated that a NO oxidation efficiency of 73% could be achieved when the loading was 50%, catalysis temperature was 140℃, vaporization temperature of H₂O₂ was 120℃, and the flow rate of H₂O₂ was 2.5mL/h. Under the same experiment conditions, the NO pre-oxidation efficiency of Fe₂O₃/SiO₂ catalyst was about 20% higher than that of Fe₂O₃/C-SiO₂ catalyst. TPR result showed that the carrier could lower the reduction temperature of active components and further reduce their agglomeration. The catalyst has a stable crystal structure, and good mechanical strength and thermal stability. ESR and XPS results indicated that the catalytic performance of Fe₂O₃/SiO₂ catalyst was better than that of Fe₂O₃/C-SiO₂ catalyst, which better catalyzed the decomposition of H₂O₂ to produce ·OH.

Modified polypyrrole (PPy) nanofibers with different diameters were synthesized by controlling the synthesis conditions and adding ARG, MO and α-CD+MO in the polymerization process, respectively. The physicochemical properties of the as-prepared PPy were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy(FTIR), nitrogen adsorption desorption analysis (BET) and zeta potential analysis. The results showed that the specific surface area of PPy with special morphology was 7—10 times higher than that of traditional granular PPy. Compared with traditional granular PPy, the modified PPy with special morphology can reach the adsorption equilibrium within 10 min at room temperature and pH=5 when the initial concentration of F^- was 3—5mg/L and the dosage was 2g/L. The concentration of F^- can be reduced to less than 1mg/L in the Integrated Wastewater Discharge Standard (GB 5749—2006). The results indicated that the control of special morphology had a great influence on the adsorption of F^- by PPy. In addition, the adsorption behavior was a spontaneous exothermic process, which can be well fitted by Langmuir model. The removal of F^- by PPy was mainly the result of ion exchange.

In order to investigate the feasibility of sewage sludge deep-dewatering by coordination of nano-CaO₂ and electro-osmotic, the nano-CaO₂ was fabricated by calcium salt method under optimized parameters firstly, and then the prepared nano-CaO₂ coupled with electro-osmotic were used to investigate the deep-dewatering of sewage sludge. The results showed that the purity, yield and morphology of CaO₂ would be affected by dispersant dosage, stirring speed, the dosage and drip rate of H₂O₂.The purity and yield of CaO₂ could reach 79.13% and 74.62% with dispersant dosage of 100mL, stirring speed of 500r/min, drip rate of 0.75mL/min and H₂O₂ dosage of 22.5mL respectively. Homemade nano-CaO₂ was spherical or ellipsoidal, with a particle size within 45—300nm. The water content of dewatered sludge could be reduced to 67.52% with self-made nano-CaO₂ dosage of 100mg/g DS, voltage of 50V, initial sludge dosage of 705g. Compared to commercially available CaO₂ under the same conditions, the water content of dewatered sludge was reduced by 10.91%.

The effectiveness of bio-purifying technology for low concentration phosphine has been verified, however many aspects have seldom been reported, such as what is the physicochemical properties of PH₃-degrading microbes and how the water-insoluble property of phosphine affects its bioconversion. In this study, some kinds of microbes with the characteristics of PH₃ tolerance or degradation were isolated and purified from activated sludge system operated for a long time, and comparative experiments were conducted on the physicochemical characteristics of typical strains and process enhancement of phosphine bio-purification system. The strains of M4 and M5 were highly similar to Stenotrophomonas and Pediococcus, respectively. When sodium lactate was used as carbon source for the activated sludge systems formed by the proliferation of M4 and M5 strains, the corresponding PH₃ removal rates were up to 28.9% and 37.9%, respectively. The addition of orthophosphate in absorption solution can moderately improve the effect of phosphine bio-purification. As coconut shell-based carbon was added to the bio-purification system, phosphine might be easily transferred from gas phase to absorption liquid, and the PH₃ absorption rate in the synergetic system was 0.0552mg/(m²·s) with the removal rate increasing to 67.3%. As activated sludge system was adopted to purify the PH₃ offgas, hypophosphate was the inevitable product of PH₃ biological oxidation, which might be further oxidized into other high-valent phosphorous compounds. After PH₃ entered the absorption system, it resulted in the increase of phosphorus in the absorption liquid, and most of the converted phosphorus might be stored as compounds in microorganisms.

N/B/Fe co-doped biochar (N/B/Fe@BC) was synthesized from corncob by thermal deposition and calcination. The crystal lattice structure, morphology, composition and other properties of the sample were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) and so on. The catalytic performance in electro-Fenton system with N/B/Fe co-doped cathode was investigated using p-nitrophenol as the model pollutant. The results showed that N/B/Fe@BC had a three-dimensional porous structure with staggered accumulation of nanosheets, and its surface defects were significantly increased compared with the undoped biochar. The catalytic oxygen reduction on the N/B/Fe@BC was dominated by the production of H₂O₂via two electrons reduction. The degradation rate of p-nitrophenol could reach 97.93%±1.62% in 120min with the current intensity of 50mA and initial pH of 3, and the apparent rate constant within 60min was 0.040min^-1, which was 2.7 times higher than that of the undoped biochar cathode. The N/B/Fe@BC cathode expressed high activity in a wide pH range of 3—9 and feasibility in different water matrix including tap water, river water and municipal sewage. In addition, after ten times cycle, the degradation rate of p-nitrophenol could still reach more than 85% in 120min with the N/B/Fe@BC cathode.

In order to effectively improve the efficiency of traditionally constructed wetlands (CW) for heavy metals treatment in sludge, constructed wetland microbial fuel cells were used for the removal of Zn and Ni in sludge, and the effect of electrode spaces on the Zn and Ni removal and the electricity generation performance were investigated. Results showed that the removal rates of Zn by CW-MFC with different electrode spacings (12cm, 15cm, 18cm and 20cm) were 84.68%, 64.56%, 66.98% and 50.23%, and the removal rates of Ni were 74.14%, 66.09%, 64.00% and 48.01%, respectively. Among them, Zn and Ni had the highest removal rate when the electrode space was 12cm, respectively, which were higher than traditional constructed wetland (CW) for 64% and 26%, respectively. In addition, under the 12cm space, the maximum output voltage and maximum power density of CW-MFC system reached 513mV and 50.76mW/m³, respectively. XPS analysis showed that the main heavy metals on the surface of the sludge were Zn and Ni, and high-valence Zn and Ni were effectively converted into low-valence substances or elemental substances. In CW-MFC system with a spacing of 12cm, the plant roots and electrodes contribute the most to the removal of Zn and Ni. In this case, the enrichment rates of Zn and Ni in the plant roots and electrodes were 23.76%, 30.97%, and 14.57%, 16.78%, respectively. This study shows that CW-MFC has a good effect on the removal of heavy metals from sludge and its power generation performance. Furthermore, it provides new ideas and references for the optimization of CW-MFC and the disposal and resource utilization of urban sludge.

The breakpoint chlorination method has the merits of high removal efficiency of ammonia nitrogen, rapid response, which was used to the fields of the chlor-alkali industry. However, dichloramine will be produced in the process of the reaction and make the residual chlorine concentration in the treated wastewater too high, and the ammonia nitrogen removal efficiency in the traditional reactor is low, which cannot meet the safety technical regulations for ion-exchange membrane caustic soda production (HAB004—2002). In order to solve this problem, a new process for the treatment of ammonia nitrogen wastewater by using high gravity technology to enhance the breakpoint chlorination method was proposed. Effects of high gravity factor, ratio of Cl/N, pH and liquid flow rate on the removal efficiency of ammonia nitrogen and residual chlorine concentration were investigated. The experimental result showed that the removal rate of ammonia nitrogen was more than 95%, the concentration of ammonia nitrogen in wastewater was reduced to 1 mg/L, the residual chlorine concentration was less than 1.5mg/L when Cl/N=11, β=30, pH=6—8 and Q_L=80L/h. The removal efficiency of ammonia nitrogen in RPB is better than other reactors, the concentration of ammonia nitrogen and residual chlorine in the treated water meets the technical regulations. The present method has a broad application prospect for the treatment of low concentration ammonia nitrogen wastewater in the chlor-alkali industry.

Ozone oxidation technology has a good application prospect in water treatment systems, but its practical application is limited by ozone mass transfer and oxidation selectivity. In this paper, enhancement of wastewater degradation with p-nitrophenol by adopting a novel rotating-microbubble reactor to break the ozone bubbles to micro size was studied . Meanwhile, the effect of various operating conditions on ozone mass transfer and the production of hydroxyl radicals from ozone decomposition was further investigated. Results showed that improving reactor speed and gas flow could accelerate the mass transfer of ozone and the yield of hydroxyl free radicals, while increasing the pH in water could also provide hydroxyl free radical yield and thus improve the removal rate of p-nitrophenol. Compared with other operational variables, the influence of rotating speed of reactor was most obvious, indicating that improving the hydrodynamic behavior of ozone bubbles could effectively improve the removal effect of p-nitrophenol. The result revealed the feasibility of the reactor to strengthen the ozone system. In addition, the addition of dimethyl sulfoxide inhibited the removal of p-nitrophenol, indicating that the indirect oxidation of ozone was an important way to degrade p-nitrophenol. The results of present study provide a reasonable guidance for the development and application of the rotating-microbubble reactor in the process of ozone oxidative degradation.

Vanadium chromium reduction slag is a typical hazardous solid waste, which produced from vanadium extraction by sodium roasting, and its resource-oriented utilization is in urgent need. A technical route of separation of vanadium and chromium from vanadium and chromium reduction slag have been proposed by Institute of Process Engineering, Chinese Academy of Sciences via sulfuric acid hydrolysis-preliminary separation of vanadium and chromium-depth separation of chromium/vanadium/iron by complexation, and a 10000-tons demonstration project was built in Pangang Group. The primary principle and process of vanadium/chromium separation in the acidolysis solution of vanadium chromium reduction slag was mainly investigated in this paper. The effect of H₂O₂ and Na₂S₂O₈ on vanadium precipitation was studied, the optimal conditions were determined by experiments. The results showed that when H₂O₂ was used as oxidant, the n(H₂O₂)/n(V) was 0.75, the oxidation temperature was 60℃, the initial pH of the solution was 2.0, the oxidation time was 60min, the hydrolysis temperature was 95℃, and the hydrolysis time was 2.5h, the precipitation rate of vanadium reached 84.2%. Meanwhile, when Na₂S₂O₈ was used as oxidant, the n(Na₂S₂O₈)/n(V) was 0.65, the oxidation temperature was 90℃, the oxidation time was 45min, the initial pH of vanadium precipitation was 2.5, the vanadium precipitation temperature was 90℃, and the vanadium precipitation time was 2.5h, the precipitation rate of vanadium reached 93.1%. The results showed that sodium persulfate was more suitable for industrial application due to its mild oxidation process, high vanadium precipitation rate and small chromium loss. The microstructure of precipitated product was obtained by SEM. The V₂O₅ product that obtained after calcination was determined to be orthorhombic by X-ray diffraction.

Analytical testing methods such as thermogravimetric-infrared spectroscopy (TG-FTIR), gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were used to analyze the flue gas generated after pyrolysis of an organic fireproof plugging material. TG-FTIR analysis intimated that carbon dioxide was the major component of the flue gas produced by pyrolysis, no matter under aerobic or restricted oxygen conditions. The reason might be that the carbon dioxide mainly came from the thermal decomposition of some inorganic components and decarboxylation of some organic components, which were less affected by oxygen. The composition and content of the flue gas pyrolyzed under aerobic atmosphere at 700℃ were comprehensively analyzed by GC and GC-MS, and 21 gas components were determined. The safety assessment of the gases may adversely affect the fire rescue work and the surrounding environment was carried out to reveal the potential hazards that may be exposed by using this organic fireproof plugging material in a fire. The present work provides a certain reference for the future development and improvement of organic fireproof plugging materials.